/* * Copyright (c) 1997 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that: (1) source code distributions * retain the above copyright notice and this paragraph in its entirety, (2) * distributions including binary code include the above copyright notice and * this paragraph in its entirety in the documentation or other materials * provided with the distribution, and (3) all advertising materials mentioning * features or use of this software display the following acknowledgement: * ``This product includes software developed by the University of California, * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of * the University nor the names of its contributors may be used to endorse * or promote products derived from this software without specific prior * written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #ifndef lint static const char rcsid[] = "@(#) $Header: /tcpdump/master/tcpdump/gmt2local.c,v 1.4.6.1 2002/06/01 23:43:53 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #ifdef HAVE_OS_PROTO_H #include "os-proto.h" #endif #include "gmt2local.h" /* * Returns the difference between gmt and local time in seconds. * Use gmtime() and localtime() to keep things simple. */ int32_t gmt2local(time_t t) { register int dt, dir; register struct tm *gmt, *loc; struct tm sgmt; if (t == 0) t = time(NULL); gmt = &sgmt; *gmt = *gmtime(&t); loc = localtime(&t); dt = (loc->tm_hour - gmt->tm_hour) * 60 * 60 + (loc->tm_min - gmt->tm_min) * 60; /* * If the year or julian day is different, we span 00:00 GMT * and must add or subtract a day. Check the year first to * avoid problems when the julian day wraps. */ dir = loc->tm_year - gmt->tm_year; if (dir == 0) dir = loc->tm_yday - gmt->tm_yday; dt += dir * 24 * 60 * 60; return (dt); }